Integrated circuit (IC) devices include the central processor unit (CPU) or a graphics processing unit (GPU) components used in modern computers. A typical IC device comprises a semiconductor die or substrate. An array of active logic device and addressable memory cell components (e.g., transistors) are disposed within the die or substrate and operably configured into circuitry with an interconnective network of conductive traces, leads and vertical interconnect accesses (vias) disposed within the IC device internally. The components interact with an exchange of data signals over the internal conductive network.
An IC device itself may exchange data signals with one or more other IC devices. In an exchange of data signals, a first IC device operates as a transmitter component and transmits a data signal to at least a second IC device, which thus operates as a receiver component, interactive with the transmitter component in a data exchange network external to each of the at least two IC device components. The data exchanges may comprise single ended transactions or a two-ended exchange, e.g., of a differential signal. The transmitter component and the receiver component may be electrically coupled for the exchange of data signals with one or more conductors.
The electrical conductors may be electrically coupled at each opposite end thereof to one or more micro-bumps, solder balls or other conductive components of a C4 package, a ball grid array (BGA) or another electronic package to which each of the IC devices are mounted electromechanically. Conductive leads electrically couple at least a portion of the active device arrays and other internal components of each of the IC devices to the conductive components of the electronic packages and thus, to the one or more conductors.
The IC device transmitter component and the IC device receiver component are interconnected with a semiconductor interposer component. The conductive components of the electronic package are electromechanically fastened to a surface of the interposer component. The conductors over which data signals are exchanged are disposed, at least over a significant part of their length, within a semiconductor die or substrate of the interposer. The interposer component may itself be fastened to a surface of a printed circuit board (PCB) electromechanically. The interposer conductors may be electrically coupled to one or more other components mounted on the PCB discretely in relation to the interposer component.
The interposer traces may have significant resistance values. Further, the silicon or other semiconductor die, matrix or substrate of the interposer component in which the interposer traces are disposed imposes significant parasitic capacitance as a dielectric material in relation to the traces. The resistance of the traces and the parasitic capacitance of its dielectric matrix contribute to losses over the traces. Thus, the fine interposer traces tend to be quite lossy in relation to sustaining signal strength over their lengths.
Passive equalizers may be used to address the lossiness added by interposer traces to circuits interconnecting IC device transmitter and receiver components. Conventional approaches implement passive equalizers with discrete components installed typically on a PCB, to which the interposer component, with the IC device transmitter and receiver components mounted thereon, is also affixed. Such approaches are described in one or more of the following references:
Zhang, et al. “Analysis and Optimization of Low-Power Passive Equalizers for CPU Memory Links,” IEEE Trans. CPMT, vol. 1/no. 9, pp. 1406-1420, IEEE (2011);
Sun, et al., “Passive Equalizer Design for Through Silicon Vias with Perfect Compensation,” IEEE Trans. CPMT, vol. 1/no. 11, pp. 1815-1822 IEEE (2011) and/or
Liu, et al. “An Embedded Common-Mode Suppression Filter for GHz Differential Signals using Periodic Detected Ground Plane,” IEEE Microwave Wireless Compon. Lett., vol. 18/no. 4, pp. 248-250, IEEE (2008). However, implementing passive equalizers with discrete components installed on a PCB demand board area on the PCB, which can displace other components and/or reduce the overall real estate available on the PCB.
Further, conductive leads and connectors are required on the PCB to interconnect the discrete passive equalizer components with the conductor components interconnecting the IC device transmitter and receiver components. The conductive leads and connectors of the PCB are electrically coupled in some relation to the conductive interposer traces, add their own lossiness thereto and may increase the effective length and lossiness thereof, which may add demands on the size, strengths, current draw and power use by the passive equalizer components.
Some conventional approaches implement passive equalizers with discrete components installed on the electronic packages to which the IC devices of one or more of the transmitter and receiver components are mounted. Implementing passive equalizers with discrete components installed on the electronic packages however demand real estate thereof. Implementing passive equalizers with discrete components installed on the electronic packages also uses conductive components, which may thus become unavailable for other uses.
Approaches described in this Background section could, but have not necessarily been conceived or pursued previously. Unless otherwise indicated, neither approaches described in this section, nor issues identified in relation thereto, are to be assumed as recognized in any prior art merely by the discussion thereof within this section.